feat(admin): 订阅列表支持一键绑定到订单（续费缺订阅治理）

tests/Feature/AdminSiteSubscriptionIndexAttachOrderIdShouldRenderBindButtonTest.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\SiteSubscription;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminSiteSubscriptionIndexAttachOrderIdShouldRenderBindButtonTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_index_should_render_bind_to_order_button_when_attach_order_id_present(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'sub_index_attach_order_plan',
+            'name' => '订阅列表绑定订单按钮测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $sub = SiteSubscription::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'status' => 'active',
+            'source' => 'manual',
+            'subscription_no' => 'SS_ATTACH_ORDER_BTN_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 10,
+            'starts_at' => now()->subDays(1),
+            'ends_at' => now()->addDays(10),
+            'snapshot' => [],
+            'meta' => [],
+        ]);
+
+        $orderId = 12345;
+
+        $res = $this->get('/admin/site-subscriptions?attach_order_id=' . $orderId . '&attach_back=%2Fadmin%2Fplatform-orders%2F1');
+        $res->assertOk();
+
+        $html = (string) $res->getContent();
+        $this->assertStringContainsString('绑定到订单 #' . $orderId, $html);
+        $this->assertStringContainsString('/admin/platform-orders/' . $orderId . '/attach-subscription', $html);
+        $this->assertStringContainsString('name="site_subscription_id" value="' . $sub->id . '"', $html);
+    }
+}